Medical Mystery

I changed out her coffee for decaf, and hid her box of soda, hoping that will help with sleep. Good thing, because tonight she made a pot of coffee before bed.

Grandma, won't that keep you up?
Nope, never does.
But it's caffeine.
That's all in your head. You're imagining that.
No, it's a chemical that keeps you awake.
Doesn't do anything to me.

Maybe the Pepsi she's drinking won't, either. (sarcasm)